Crucible-furnace



(No Model.)

. C. C. CARROLL.

GRUGIBLB PURNAGE.

No. 376,632. Patented Jan. 17, 1888.

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illlhf IMM E2 'E Miren STATES CRAFT C. CARROLL, OFMEADVILLE, PENNSYLVANIA.

CRUClBLE-FUYRNACE.

SPECIFICATION forming part of Letters Patent No. 376,632, dated .l'anuary 17, 1858.

Application filed January 31, 1587. Serial No. 226,057.

.To all whom it may concern:

Beitknown thatI, CRAFT C. CARROLL, achizen of the United States, residing at Meadville, in the county of Crawford and State of Pennsylvania, have invented certain new and useful Improvements in Crucible-Furnaces; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable' others skilled in the art to which it appertains to make and use the same.

My invention relates to smelting-furnaces; and it consists in the construction and arrangement or combination of the parts,which will be more fully hereinafter described, and pointed out in the claim.

The object of my invention is to provide a furnace having chambers in which high and different degrees of heat can be produced and maintained by natural or artificial gases or by hydrocarbon oils.

Preferably I construct my furnace so that it can be readily moved from place to place, but it may be constructed so as to remain fixed and stationary.

I am aware that lfurnaces have been constructed with more than one chamber and for substantially the same purposes and objects which I have found can be successfully accomplished with my furnace, but, so far as I know, with only partial success.

I am also aware that furnaces have been `constructed so as to heat the gas used when found desirable, but not in the way I provide for heating` the same. A

I have found that with afurnace constructed and operated as yhereinafter described any required degree of heat can be obtained, and that such differences of temperature can "be maintained in the chambers as may be desired.

In the accompanying drawings, illustrating my invention and forming a part of this specification, and in which the same letters indicate the same orsimilar parts, Figure 1 is a front elevation of my furnace, and Fig. 2 is a vertical section of the same.

On said drawings, A represents the outer easing or jacket of my furnace, which may be made of any suitable material, but is preferably made of Russia sheet-'iron suitably bolted or riveted together, and B the inner portion or lining of the same, which may be made of (No model.)

clay or fire-brick. Thislining rests on a iiange formed by turning thejacket A inward at its bottom, as shown at a2, and its cap or top B' is provided with, a flue, b, which registers with a pipe, a, mounted on and secured to the top of casing A. Between this cap and the top of the casing is arranged a sliding damper, a', for controlling the draft through the flue b and pipe a. The interior .of the furnace is formed into two heatingchambers, C and D, which are provided with removable doors C' D', formed of fire-brick or clay and provided with curved handles c d and with isinglass peepholes c and d, through which the interiors of the chambers may be inspected.

' The walls of the chambers C and D are separated by an annular strip or ring of fire-brick, C. Extending across the space between the inner walls of this ring C'A from side to side and preferably formed integral therewith is a triangular or V-shaped bridge, c', of sufficient width Von its upper side to support a fiask, as G, Fig. 2, leaving on either side openings for the passage of heat, as shown. The bottoni of thc chamber D consists of" an annular ring, A2, provided with a bridge, d', leaving openings on either side thereof, as shown, for the passage of heat.

A combustion-chamber, A', is formed below the bottom Az of the chamber D, as shown, and consists of a thin metallic shell of a diameter sufficient to allow the casing A, which is securely riveted thereto,` to enter the same at its upper end a short distance for securement.

Entering at one side of the combustion-chamber A', and about midway'froni its bottom and the lower surface of the annular ring A2, is a feed-'pipe, f3, which may be connected to any suitable source of supply of gas, preferably by means of a tube or pipe, e, of rubber or other suitable material, adapted to be removably secured thereto.

A revoluble perforated coupling, FF, connects the pipe E3 to a short pipe, E, of larger diameter than pipe E3, the pipe E connecting lwith the T-joint F', which carries the burner E', which may be of any ordinary form. Connecting with the T-joint F is a vertical pipe,

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F, passing up through the fire-brick or clay subset-ve the same end.

to a horizontal pipe, F", which passes across the upper chamber, C, and protrudes through the casing a short distance, and is arranged to receive the perforated coupling El, to which is attached the pipe E, as shown in Fig. 2. This coupling 112, with its pipe E, is transfen able from the pipe F to the pipe E, and vice versa, as may be desired.

Then the gas is admitted through the pipe E, the outer end of the pipe F may be closed by means ofthe eapj, as shown in Fig. 1, so that the gas cannot escape at that point; also, when the gas is admitted through the pipe F and the perforated coupling lil and the pipe E, the outer end of pipe E may be closed by said cap; or, if preferred, cocks or Valves G and may be employed in the pipes E and l1, as shown in Fig. l, in lieu of the capf and I have shown in Fig. 2 a iiask, G, located in the upper chamber of the furnace and resting on the bridge c', and in the lower channber, l), a erueible, H, resting on the bridge d; but it will be understood that I do not limit myself to the use ofsuch devices in such chambers, as other uses may be made of said furnace, and other means than those shown may be utilized instead of the flask or crucible shown.

l contemplate using natural and artificial gases and hydrocarbon oils for fuel in my furnace, and will now describe the manner of employing` the same. u

\Vhen natural gas is to be used for heating the furnace, the valve or cock G is opened and the gas admitted through the pipes c, li, and E. rl`he air entersthrough the perforated coupling E and unites with the gas in pipe E and passes on to the burner E', the air acting to produce perfect combustion of the gas.

\\vhen ordinary or manufactured gas is employed, it is desirabie to heat both the air and gas before they reach the point of combustion. '.l'o effect this the valve or stop-cock G' is closed, the valve or cock G opened, and the gas admitted through the upper pipe, li, and the air through the perforated coupling l), and together pass through pipes F" and F, elbow l F, and T-joint lf to the burner itl', where they are ignited.

f have found in practice that by the use of either of the gases named in a furnace conA strueted as above described and in the mani ucr described the temperatures in tho chami bers C and D arc very different, due to the different applications of the heat thereto, the lower chamber being closer to the burner or source of heat, will necessarily be of higher temperature than the upper chamber-as, for instance, if the temperature in chamber D reaches 1,3000, the temperature in chamber C will be about 1,1000.

I have found this furnace especially useful in dentistry, because ofthe high and different temperatures which can be obtained and maintained therein for melting aluminum and other metals requiring very high degrees of heat to melt tlieimand also in the formation of crowns, bridges, and dental plates where different degrecs of temperature are required.

It' it is desired to melt a very refractory metal, it is placed in a crucible, as H, in the lower chamber, and the heat is applied until the required degree is obtained. \Vhilc such melting is going on a flask may be placed in the upper chamber, as G, and the ordinary and usual worl; of dentistry proceeded with. I do not. however, limit the use ofsaid furnace to dentistry, as it is obvious that on account of its lightness and compaetness it may be applied to many other uses.

it is obvious that many minor changes in the construction and arrangement of the parts may be made and substituted for those shown and t cscribed without departing from thenature or principle of my invention.

Having thus described my invcntion.whatI claim, and desire to secure by Letters latcnt, is

A smclting furnace comprising a metallic outer casing having a tire-brick or clay lining, upper and lower heating chambers having iloors formed ofbridges,horizontally-arranged fuel-feeding pipes entering near the base and the top thereof,and provided with one or more perforated couplings for the admission of air, a Verticallyarrangcd pipe within the tire-brick or lining for heating the air, or the air and gas, a damper for coi'ii'rolliug the consumption of fuel by closing or opening` the flue, and a gasburner, substantially as described.

fn testimony whereof f affix. my signature in presence oftwo witnesses.

, nn intros', iii im :u aan.

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